Issue #17261: Ensure multiprocessing's proxies use proper address.

Lib/multiprocessing/managers.py

@@ -731,6 +731,7 @@ class BaseProxy(object):
         elif kind == '#PROXY':
             exposed, token = result
             proxytype = self._manager._registry[token.typeid][-1]
+            token.address = self._token.address
             proxy = proxytype(
                 token, self._serializer, manager=self._manager,
                 authkey=self._authkey, exposed=exposed

Misc/NEWS

@@ -138,6 +138,8 @@ Core and Builtins
 Library
 -------
 
+- Issue #17261: Ensure multiprocessing's proxies use proper address.
+
 - Issue #18343: faulthandler.register() now keeps the previous signal handler
   when the function is called twice, so faulthandler.unregister() restores
   correctly the original signal handler.